Apparatus for holding and positioning a combined mask and screen



Sept. 29, 1953 w. c. HUEBNER 2,653,510

APPARATUS FOR HOLDING AND POSITIONING A COMBINED MASK AND SCREEN FiledFeb. 24, 1951 2 Sheets-Sheet l n u n I n I n u n I I I u l n I I I II ln 1 u u i I n I n I II v i. @l;

2b ii: I

IN V HV TOR. W/ L L mm C. Hue-3mm Arr-mews Sept. 29, 1953 w. c. HUEBNERAPPARATUS FOR HOLDING AND POSITIONING A COMBINED MASK AND SCREEN 2Sheets-Sheet 2 Filed Feb. 24, 1951 INVENTOR. WILL mm 6. HusB/VEB BY 9/ ME24;

Patented Sept. 29, i953 UNITED STATES PATENT OFFICE APPARATUS FORHOLDING AND POSITION- ING A COMBINED MASK AND SCREEN William CarlHuebner, Mamaroneck, N. Y.

Application February 24, 1951, Serial N 0. 212,623

16 Claims. 1

This invention relates to an apparatus for use in making fractionaland/or half-tone type exposures of an image on a light-sensitizedsurface and, more particularly, to an improved apparatus for holding andaccurately positioning a combined mask and screen for making suchexposures.

The photographic reproduction of an image upon a sensitized surfacepresents many problems, especially where such reproductions are to beused in printing, and these problems are accentuated when the image isin color and not simply black and white. For example, it is frequentlynecessary to have a relatively long exposure to bring out details inshadows of an image, while at the same time care must be exercised notto overexpose and thus lose detail in the lighter areas. Also, inpreparing color separation members for use in printing by the half-toneprocess, it is desirable to be able to control both the sizes and thepositions of the dots or exposed areas on the sensitized surfaces of theseveral color separation members relative to each other to provide moreauthentic color correspondence and prevent moir pattern and muddyappearance in the composite reproduction. In my prior patents, forexample, No. 1,060,982, issued May 6, 1913, and No. 1,780,191, issuedNovember 4, 1930, are disclosed combination mask and screen membershaving transparent and opaque areas in various predetermined patternswhich may be moved to preselected positions for securing fractionalexposures and/or to serve as screens in preparation of color separationmembers. These prior devices have enabled the achievement of greatlyimproved results in photographic reproduction of images, but with theincreased use of color in printing and the demand for finer detail andstill greater correspondence with the color of the original image, ithas become necessary to effect further improvements in the mode ofhandling the combined mask and screen members so as to achieve betterresults with the expenditure of less effort.

An object of this invention is, therefore, to provide an improvedapparatus whereby a member, composed of minute alternate transparent andopaque portions, may be both rectilinearly and rotatably shifted toaccurately predetermined positions relative to a sensitized surface thusserving either as a fractional mask for sequential exposures of selectedareas of the sensitized surface or as a screen in the nature of ahalf-tone screen for the preparation of either black and white or colorseparation members capable of utilization in mechanical orelectronographic printing operations.

Another object of the invention is to provide an improved apparatus ofthe type defined in the preceding paragraph and wherein the combinedmask and screen member may be positioned at different selected distancesfrom the sensitized surface to provide spaced minute exposed areas ofdesired sizes, the said mask and screen being so supported as to becapable of being rotated to different angular positions andrectilinearly shifted in any of the dine-rent angular positions.

A further object of the invention is to provide an improved apparatus ofthe type mentioned above in which the combined mask and screen member iscomposed of opaque lines intersecting at right angles to providerectangular transparent areas therebetween and the member is sosupported as to be rectilinearly shifted in two directions extending atright angles to each other between either of two predetermined positionsin each of its directions of movement so that a transparent area may besequentially moved to four separate positions in juxtaposition Withrespect to each other and in each such po" sition the previously exposedarea of the sensitized surface is covered, whereby four separateexposures of the image to be reproduced can be made upon a singlesensitized surface which separate exposures are juxtaposed to providebut one composite image, the areas beneath the transparent portionsbeing exposed to the image which is to be reproduced for either the sameor different lengths of time.

A still further object of the invention is to provide an improvedapparatus as defined in the preceding paragraph and wherein the mask andscreen member may be rotatably adjusted to any desired angular positionand locked in that position without interfering with the rectilinearmovement thereof.

An additional object of the invention is to provide an improvedapparatus as defined in the two immediately preceding paragraphs and inwhich a means is provided to efiect a preselected separation between thecombined mask and screen member and a means for holding a body having asensitized surface, which separation does not, however, affect themechanism for angularly or rectilinearly moving the mask and screenmember.

The invention further resides in certain novel features of theconstruction and the combination and arrangements of the parts of theapparatus in which the invention is embodied, and further objects andadvantages thereof will be apparent from the following description ofthe present preferred embodiment of the invention taken in conjunctionwith the accompanying drawings, in which identical parts in the severalviews are designated by the same reference characters, and in which:

Fig. l is a front view principally in elevation but with certain partsbroken away and others snown in section to more clearly disclose theconstruction of the present preferred form of the apparatus, thetransparent and opaque portions of the combined mask and screen beingillustrated at a greatly enlarged scale in one corner thereof;

Fig. 2 is a fragmentary sectional view taken substantially on the line22 of 1 and illustrated on a scale twice that of Fig. '1;

Fig. 3 is a fragmentary view, principally in side elevation, of theapparatus shown in Fig. 1, the view being to the same scale as Fig. 2-with parts broken away and others shown in section; and

Figs. 4, 5, 6 and 7 each represent a greatly enlarged elevation of anarea of the combined mask and screen illustrating the four separatepositions the transparent portion of the selected area may take as aresult of rectilinear movement of the screen in two directions at rightangles to each other.

The apparatus of this invention for support-. ing a combined mask andscreen is adapted to be used with well-known darkroom type cameras; forexample, such as disclosed in my prior Patents 2,406,770, issuedSeptember 3, 1946, and 2,458,269, issued January 4, 1949. It istherefore deemed unnecessary to describe the general construction ofsuch cameras and the manner in which the novel apparatus of thisinvention is supported in operative relationship with the other elementsof the cameras since these details may be readily determined byreference to the aforesaid patents. It is to be understood, however,that while the apparatus of this invention is especially suited for usein cameras of the type disclosed in my above-mentioned patents, it is ofcourse not limited to use in such cameras but may be employed inconjunction with other cameras and photographic devices of similarnature.

Referring now first to Figs. 1-3, it will be seen that the apparatuscomprises a frame member 18 which is preferably of plate-likeconfiguration and has a large circular central opening H. Supported uponone face of the frame member H at substantially equally spaced dis-.tances and intermediate the central opening and the periphery of theframe are a plurality of rollers l2, four such rollers being shown intheillustrated embodiment. These rollers are ro.

tatably mounted upon studs is, extending ou-twardly from the plate [0,and are provided with bearings ii to permit free rotation of therollers. The periphery of each roller is grooved and supported in thesegrooves of the rollers is a circular plate-like member or disk It whichis therefore freely rotatable relative to the frame member 1 0. Theplate-like member or diskl has a rectangular central openingsubstantially aligned with the circular opening I I in the frame member[0, thus permitting unimpeded transmission of light therethrough. Theforward face of the plate or disk I5 is provided with a plurality ofbuttons or spacers l6 upon which a pair of superposed members or platesIT and [8' is slidably supported for rectilinear movement in directionsat right angles to each other, as hereinafter described.

The members I! and I8 have central, rectangularly shapedopeningsdisposed in substantial alignment with respect to each other and to theopening through the disk l5. Extending over the central opening I9 ofthe outermost member i8 is a combined screen and mask member 20 ber ismade removable.

which is removably and adjustably supported on the member 18 by suitablemeans generally designated 2!. In the illustrated embodiment, the maskand screen supporting members 2| each comprise an adjustable block 22having elongated slots 23 in which are positioned screws 24 that arethreaded into tapped openings of the member l8, The edge of each blockor member 22 adjacent the combined mask and screen 20 is undercut toengage over the adjacent edge of the mask and screen, which edge is hereshown as bevelled, so that the blocks 22 removably securely hold thecombined mask and screen in place. In the illustrated embodiment, eightclamping means 2l are employed, two at each side of the opening [9 andthe adjustable block :22 of each clamping means 2| can be readily in-..dividually moved to and from clamping engage-1 ment with the combinedmask and screen 20 by actuation of an associated adjusting screw 25;which is threaded through a stationaryv block 26. secured to the memberl8 adjacent each block 22. It will be seen that by such a constructionthe mask and screen member 20 is supported and accurately positionedwith respect to the aligned openings through the members I 0, 15, I1 andI8 for control of the passage oflight therethrough. g

In the illustrated embodiment, the combined mask and screen 26 is formedof a transparent; plate 21 of glass or similar material. on which areprovided a series of opaque lines intersecting: at right angles andwhich lines are equally spaced: from each other with the spacing betweenthelines equal to the thickness of the lines. There is thus provided acombined mask and screen having uniformly spaced, rectangular, transeparent portions 28 representing one-fourth of the total area of themember 20 with the remaining three-fourths of the area of the saidmember being opaque as indicated at 29, theopaque portions resultingfrom the said intersecting lines. and mask member 20 can be formed inany suitable manner as, for example, by scribing the surface of theplate 2-1 with a dividing engine, by photographic reproduction, or-byother suitable means as will be readily apparent to those skilled in theart.

The widths or thicknesses of the lines comprising the opaque portions29, and which correspond With the widths of the transparent portions 28-of the combined mask and screen member 20, will of course be selected inaccordancewith the nature of the work for which the mask andscreenmember is to be utilized and it is for this reason that the said maskand screen mem- By way of example but without limitation thereto andsolely to show the order of the size of the lines and transparentopenings, one suitable member 25); as lines to the inch so that thedistance between longitudinal centers of the lines is- .008" with eachline and transparent area having a Width of .004. While thecombined-mask and screen has been shown as formed ofglass with opaquelines provided thereon, it will be evident that it mightalso be possibleto employ a member in which the transparent areas are openings betweensolid= opaque portions, as, for example, by having thelines provided inthe form of intersecting wireswith the transparent portions being theopen-- ings therebetween.

As mentioned heretofore, themembers or plates I1- and- I8 are supportedfor rectilinear move:

The opaque portions of the screen a ments at right angles to each otherand this enables the screen and mask member to be correspondingly movedto thus dispose the transparent portions 28 successively in alignmentwith different areas of a, sensitized surface positioned adjacentthereto, as will be hereinafter described. For this purpose, the disk I5is provided with two pairs of spaced rollers 30, 3| in rolling contactwith opposite edges of the plate IT, in this case the upper and loweredges as viewed in Fig. 1. Consequently, the plate I1 is guided forrectilinear movement transversely of the disk E5. The plate I! isprevented from displacement away from the surface of the disk l5, aswell as being additionally guided in its movements, by blocks 32 securedto the disk l5 and having the forward edges undercut to engage over theadjacent edges of the member or plate I! in sliding relationship. Theplate [8 is supported upon the plate I! and guided for rectilinearmovement at right angles thereto by means of spaced rollers 33 and guideblocks 34 disposed adjacent the vertical edges of the plate l8, asviewed in Fig. 1, and supported upon the plate [1, thus supporting andguiding the plate [8 in a similar manner to that in which the plate I!is supported and guided. It will be apparent from the construction justdescribed that, as viewed in Fig. 1, the plate I! may move horizontallya limited amount but cannot move vertically, while the plate l8 may movevertically but cannot move horizontally.

Each of the members or plates l1 and I8 is adapted to be moved in itsrespective rectlinear direction between either of two predeterminedlocations or positions so that the transparent areas 28 of the member 20can each assume four difierent positions in exact juxtaposedrelationship with the result that four movements of the screen and maskmember 20 permit a complete exposure of a sensitized surface placedadjacent the said screen and mask member by four separate exposurestherethrough. For example, a given transparent area 28, in the positionof the members I! and (8 illustrated in Fig. 1, may occupy a position asshown in Fig. 4. By moving the member l8 vertically to its otherposition, this transparent portion 28 can be made to move to a positionvertically below its previous position and in exact juxtaposedrelationship with respect thereto as is indicated in Fig. 5. For thelatter position of the member 18, the given transparent portion 28 canbe made to assume the position as indicated in Fig. 6 by moving themember I! from its position shown in Fig. 1 to the other of its twopredetermined positions, while leaving member I! in this last-mentionedposition, and returning member l8 to the position illustrated in Fig. 1will move the given area 28 to the position illustrated in Fig. 7.Consequently, the member 20 can thus be used as a mask for producing acomplete exposure of a sensitized surface by moving the mask member 2!!to each of the positions just mentioned and effecting an exposuretherethrough so that the complete exposure of the entire sensitizedsurface is in the form of four separate juxtaposed exposures. Anysuitable means may be employed for supporting the sensitized surfacerelative to the mask 20 during such operations, but where the surface isa film, it is desirable to place the latter and the mask member 20 incontact during the exposures. One suitable means for effecting this isthe apparatus shown in my prior Patent 2,139,956 issued December 13,1938, although it will be understood that other apparatus may beutilized for this purpose.

In order to effect the above-mentioned movement of the member or platel8 to and from its predetermined positions, the member or plate [1rockably supports a cam means which is operative upon the lower edge ofthe member [8, as viewed in Fig. l, to effect movement of the saidmember. As illustrated, an arm 35 has a hub portion 3511 provided withan eccentric bore which is rockable upon a stud 35b mounted upon themember [1 adjacent the lower edge of the member l8. The hub 35a of thearm 35 is rockable in the bore of a block 36 so that rocking of the armcauses movement of the block 36 relative to the plate H. The upper edgeof the block 36 bears against a second block 31 which in turn engagesthe lower edge of the member or plate I8 so that, as the arm 35 isrocked, rectlinear movement is imparted to the member 18 in a verticaldirection as viewed in Fig. 1. In order to restrict the movement of theblock 31 to movement in the rectilinear direction just mentioned, thelatter is received in and guided by a rectangular opening in an arcuatemember 38 supported upon the member or plate I! and having a portionoverhanging the member or plate l8. Adjacent the upper edge of themember I1, opposite the motion producing means just described, aredisposed a pair of resilient means, generally designated 39, acting uponthe member I8 to return the latter to its initial position whenpermitted by rocking of the arm 35. As illustrated, the resilient means39 each comprise a compression coil spring 40 supported between suitablemembers 4| and 42 carried by the members I! and I8, respectively.

The arm 35 has an elongated portion 43 of reduced thickness whichcooperates with the arcuate member 38 to provide a means for accuratelydetermining, by touch, the position at which the member I8 is locatedand the proper extent of movement of the member 18 to dispose it at theother of its two predetermined positions, it being 5 remembered that theapparatus is intended for used in a darkroom as part of a camera. Forthis purpose, the member 38 is provided with an arcuate segment 44having two spaced bores 45 therein with which a pin or projection 46 onthe portion 43 of arm 35 is adapted to be selectively engaged, theportion 43 having sufiicient resiliency to permit removal of the pin 46from one opening 45 and re-engagement with the other opening when thearm 35 is arcuately moved to slide the pin or projection over thesurface of the segment 44. The distance between the two spaced openings45 is so related to the eccentricity of the hub 35a of the arm that themovement imparted to the member l3, when the portion 43 is moved fromone to the other of the holes 45 is exactly equal to the width of atransparent portion 28 of the combined mask and screen member 23. Thus,the member 20 can be accurately moved vertically, as viewed in Fig. 1, adistance equal to the width of a transparent portion 28. Moveover member18 is locked in either of its two positions through the cooperation ofthe pin 46 with an opening 45.

I The member I? is provided with a similar positioning and locking meanscomprising an arm 41 having a hub rockably supported on the disk l5 by astud 41a. The stud 41a, like the stud 35b, is eccentrically disposedwith respect to the hub of arm 47 and the hub is rockable in the bore ofa block 48 which engages with a block een seti e; w t anedeez o the.membe i! to efiect rectilinear movement of the latte at ere. ngles. tothe. rectilinear mo emen of member t t. M vement i. h p nch 4:3 s on: trined; o a. reet iinear directi n it be ng. slid.- bl-sr re e ed: areetenenler open ng. i ar r d,. er espe dine wi h t e pr ,d. member 3 e.member 51 ears es arc ite: or on. 51- hail ng. a p ir of paced beres 5%with which a. p n or projection on el ngated extensi n portion. 53. ofarm Mr eeepe ietes to l cate and l k t e arm. 41 in either ettwepredeterm n d p s i s. The ppesi e dge .Q-the member it; is acted u on.-byresili nt means. 5. la to the means. as. and-1 e mp eitecte t and. theposition of the member' d teizmined. solely by h ense of touch- Moeeienthem mber it and arm it" a ocke ither pr dete mined pos tion nc ar 41endathe opening 5.2: cooperat n the me mannet. ai ido-thecorrespondingparts for moving themembe; tit.

The areiiete. member iiiand 5. a made ree movable, .ier examp e by be ne red. by screws or the like to the members 38, and 5G, ne pee ieely- Ths enables re dy repl c ment of the ere ateportions t4. and Si by thering he.- spaeina et heir p nin s, such as t nd t2, 0t difii r nt dimensons, wh ch d mensions rresp nd w th he d m n i n f h trensp rent openins at. di er nt an ateen members 28- wh-ieh may be til zed. That.

s.- tosay,.wih n=. he. mask and creen mem r 20.-

is; replaced, by another hav ng. s. Opaq nd transparent por ons of diffent d mensionsfrom tho e the. member p eviou ly sed, the ar a e members:it and 51. must likewise be replaced. so. the movemen s imparted to thecombine mask and screen will be of proper extent to. disp se the:transparent p rtions inju taposition when inheir veral. prede er p stion W ile only the r na p rtions at. an i eed: to. than be chan e othat h m m ers; such st, and. 5.5%. may ema n in m ce, some in. staneesit be desirable to make he are e e portions. and the correspondingembers 3.8;. 5.0 removable oge her, in which v t e p io s 44 ands!beinteeral withithe corr sponding:

mfimbersjfiiandshil, respectively. Moreover, while;

the. extent oi movement of the; combined mask and, screen, member: 23in,the two rectilinear directions is preferably equal. tothetransverse-dbmension, of. a transparentportion. ofthe member: til, it.will be apparent. that the sam result s chieved. ii. the. movementsofthemembers. I?!- and l8 be equal tothe width of such transparentopenings multiplied by an odd integer. In such an event any giventransparent opening will: take up successive positions which are notadjacenteach other but which are spaced from eachc other bypredetermined multiples of its width. It will be readily seen, however,that the four positions oi. the arms 35 and 41 will 8 till provide.teurp sitiensof he meshend re n member 2.0 s ch that a sens t zed Srt-see d a ent here o ee ve f u ac i l ex 13 ures thepecn, which taken.to ether. will come ens. omposit exp sur of th enti sur- In addition tothe above mentioned rectilinear mete oi the mem er 20 t e la er mayalso; be. r tate to any des r d an ul r osi ion nc it ill be r memb redh e disk 15. is rotatably u po ted upon e fr me mem e it byhe pollers,I21. Mor.eover; since the above described; armsv 3,5 and 4:7- lock the:mask and; screen. meme er it in an: ad usted p s t o thi n u ar psitienine o the. dish it per it mpend angular positioning of the member20 ithout. other movement. Nevertheless, the combined m shend screen memZilm v e d me ilinearly to any of its four predetermined positionewhendisposed atany angular positiom In order toiretainz the dis}; t5; and;hence thamem; her it. t n a ed n ular 1 .51 tion and to indicate thatpesition, a combined ins di atiiie and clam in mean -p v d 9 1 he fr me.memb r 5 jacent. the p phery of! the dish l5.

Inthe. ill,ustratedembodiment, this, means @emprises a. block 55. theforward edge t hich is adapt-ed t e t a cla p g; a n. up h p phe y of te-disk it when h clam n S e 53?, passing therethrough and threaded intothe name member it is tightened. The forwardedge of the clamping block56, where it overlies the diskti, preferably provided. with suitablemeansv cooperating; With.- indicia; onthe disk t5, to the adjustedposition ofthe; latter. is forward edge oi. the block 55- is shown. g anotchor: recess, 53 therein having; one s. radial with respect tothedish 1-5; for alignment: with radiaL indicia 53 provided upon h di h.

The-indieiaiil may be provided at any desiredangularly spaced: distancesbut, in the preferred embodimentthey are at intervals of- 1 -5 to facilitate positioning, of the combined mask and: screen 20. at angularlocations separated from; each. other by either. 1-5 or 30 That 1 5 0say, when themember 201s. toibe, used as a. screenfor. reproduction in:the half-tone system it willbe spaced from a sensitized surface on whichthe. dots 0r exp sedare sare to be p o uc d a d a exposure made with.the disk [5 in one predca termined, angular position. If thehalf-tonere.- production is.- to.be, in. color, successive reproduce tions ofthis. nature are made. for each; color, with, the, use oi suit ble.filters in. conjunction. h. he. member 20;. a d. it t e latterdisposedat di erent' aneula pesi o f suecessivecolor separationexposure. Hence, theresnlting exposed portinns or areas up n the ED-arate sensitized surfaces, when used together in. the, composite p ctue. ccura ly rep u e he ori inal mage. an do.- n t mprop r y om in in.the, hi hly objecti n b e moire patt rn- F example, the disk |5 may bepositioned andclamped. as. shown in Big. 1 for efiecting an exposurethrou h the mem er 211 fo th black p tions. oi an image. The clampmeans. 55 is then.

released and. the disk L rotated 15? to. the.

diciurn. marked. Yellow and clamped at that. ppsitionifor eff ctin the.exposu rr nding to. that. color. Thensuccessive exposures are made. forthe. blue and. red (10iiriponents.ofv the. ima e by rotating the dis};15 from. the position:

marked Yellow to effect the Blue exposure and 30 from the Blue to effectthe Red exposure. In each of the above-mentioned exposures it will beunderstood that suitable color filters will be employed. If desired, themember 20 may be moved rectilinearly as above described in any of itsangular positions, as will now be apparent.

In addition to the above-mentioned movements of the combined screen andmask member 2!], it is frequently desirable to vary the separationbetween the member 20 and the sensitized surface employed therewith tothereby vary the size of the dots or exposed areas formed by thetransmission of light through the transparent areas 25 of the member 20.This additional movement may also be readily achieved in the improvedapparatus of this invention. by operation of a single manually movablemember. In the illustrated embodiment, as well be seen especially withrespect to Figs. 2 and 3, the frame member In toether with disk l5,members ll, 18, and the combined mask and screen member 29 are allsupported upon a means, generally designated 59, adapted to support abody having a sensitized surface. This means 59 may be of anyconventional construction, for example, such as disclosed in myaforementioned Patents 2,406,770 or 2,458,269, and hence the detailsthereof need not be described. It is sufficient for present purposes tonote that this sensitized surface supporting means 59 is suitablysupported and normally stationary and hence provisions are made foreffecting movement of the frame l and the associated mask and screenmember 2:; relative thereto.

Referring to Fig. 3, it will be seen that the frame member IQ rotatablysupports a shaft as which extends through the frame member if! and anattached reinforcing member 6|. The shaft 56 is prevented from axialdisplacement relative to the frame member ID and the member 5| by havinga collar 62 bearing upon the face of the reinforcing member 6! and byhaving the forward portion of the shaft 69 provided with anindicia-bearing dia1 63 so as to be rotatable with the shaft adjacentthe forward face of the frame member ID. The forward or outer end of theshaft 69 is formed with a polygonal surface 69a for reception of awrench or other tool by which VI the shaft may be rotated and the shaftis journalled for rotation and axial movement in the supporting means 59for the light sensitized surface. The right-hand end of the shaft 60, asviewed in Fig. 3, is provided with an axially elongated pinion 64 whichmeshes with a rack 65 attached to a vertically extending member or bar65. The member or bar 66 is guided for vertical movement by bracketmembers 61, carried by the supporting means 59, and is provided adjacentthe top and bottom thereof with racks 68 and 69 which are disposed atright angles with respect to the rack 65. The racks 68 and 69respectively engage pinions 10 and H rotatably supported upon the frameof the supporting means 59. The pinion I9 meshes with a rack l2connected with a horizontally extending member 13 which, in turn, isconnected to the reinforcing member 6! and hence with the frame member#0. The pinion H meshes with a rack M carried by a horizontallyextending member '55 secured to the member 6! adjacent the lower end ofthe latter, as will be seen in Fig. 2.

It will be evident, therefore, that rotation of the shaft 60 causesvertical movement of the rack 65 and member 66 which, in turn, causesthe racks 68 and "59 to rotate the pinions 10, H thereby causing rack 12and 13 to produce horizontal movement of the frame 10, and the combinedmask and screen member 29 carried there by, to and from the supportingmeans 59. The frame member 19 and the members supported thereon aresupported and guided in their movement by having the member 13 slidableupon the upper bracket 61. Suitable slide guide means may also beprovided at the other side of the apparatus if necessary or desirable.

The dia1 53 is provided with suitable indicia cooperating with astationary indicium or arrow 16 on the face of the frame member [0 toindicate the distance between the combined mask and screen member 29 andthe means 59 for supporting a sensitized surface so that successiveexposures of such sensitised surface can be made with differentpredetermined spacings between the member 20 and the said sensitizedsurface, and these spacings or separation can be accuratelyre-established for corresponding successive exposures if desired.

It is believed that the manner in which the apparatus of this inventionmay be utilized will be readily apparent to those skilled in the artfrom the above detailed description. Nevertheless, it is desired toemphasize some of the more common uses of the apparatus. For example,the device may be employed with the member 2!! utilized as a fractionalmask to effect fractional exposures upon a sensitized surface. This maye effected by disposing the apparatus as shown in Fig. l with asensitized surface held substantially in contact with the member 29 byany conventional means, for example, such as disclosed in my priorPatent 2,139,956. With the apparatus thus positioned, an exposure ismade, at which time one of the transparent areas or portions 28 will bedisposed in the relative position represented by Fig. 4. Then the mask20 can be moved vertically downwardly a distance equivalent to the Widthof one of the transparent openings or areas 28 by moving the lever 41 toits second position so that the said one of the transparent portions 28is as shown in Fig. 5, Whereupon a second exposure may be made upon thesame sensitized surface. This exposure may, if desired, be timeddifferently than the first exposure. A third exposure may then be madeupon a third unexposed area of the sensitized surface by moving thelever 35 to its second position, thereby placing the said transparentarea or portion 28 in a location as represented in Fig.

6. The third exposure may have a time interval still different fromeither of the two prior exposures or may be the same as either of theprior exposures, depending upon the nature of the effect desired. Afterthis exposure is completed, the mask 20 may be moved to its fourthposition by returning the arm 41 to its position as shown in Fig. 1 sothat the said transparent area or portion 28 is then at a position asrepresented in Fig. '7. When this exposure is effected, which may be atany desired time interval, the entire sensitized surface will have beencompletely exposed with each of the four separate exposures injuxtaposed relationship. It will be understood, of course, that ineffecting movement of the mask member 20 relative to the sensitizedsurface a separation should be introduced therebetween to prevent injuryto the sensitized surface, as will be apparent from the disclosure in myprior Patent 2,193,956.

In addition to being employed as a mask for fractional exposures, theapparatus of this invention permits the member 20 to be utilized forforming exposures in the half-tone system of reproduction which isespecially advantageous for use in preparing color separation members tobe utilized in color printing. When thus employed, the disk of theapparatus is set to a predetermined position corresponding with thecolor separation member to be prepared, as, for example, at the positionshown in Fig. 1, if the black color separation member is to be prepared.In thus employing the member 20, it will normally be spaced from thesensitized surface, the extent of the spacing being preselected andreadily achieved for any desired value by means of the dial 653 inconjunction with the stationary indicium 16. The extent of the spacingbetween the member 2a and the sensitized surface will determine the sizeof the exposed areas or dots produced while the-angular position of themember 20, as effected by moving the disk IE, will enable the separatecolor separation members to have their exposed areas or dots inpositions such that moir pattern is avoided. It will be evident that inemploying the apparatus in this manner the member may be left in any ofits rectilinear positions for each of its separate angular positions or.it may be moved to any of its four rectilinear positions throughmanipulation of the arms .and 47. Moreover, the separation between thescreen 26 and the sensitized surface for any given angular position maybe the same or difierent fromth'at of the separation for other angularpositions.

While the invention has been described in-considerable .detail withrespect to one specific embodiment and to various modes in whichthatembodiment may be utilized, it will be recognized that variationsand modifications may be made in both the structure and mode ofutilization thereof without departing from the spirit of the invention.Thus, means other than specifically shown and described maybe employedfor rectilinearly positioning and locking the members I] and [8 in theirpredetermined positions. Similarly, mechanism other than the racks andpinions illustrated may be utilized for effecting the desired separationbetween the combined mask and screen member 20 and the means 59 I forsupporting the sensitized surface. These and other changes, which areconsidered equivalents of the construction illustrated and described,are deemed to comewithin the ambit of the invention Consequently theinvention is not to be considered as limited to the specific details ofconstruction here illustrated and described except as required by thespirit and scope of the appended claims.

Having thus described the invention, I claim:

1. An apparatus of the type described for positioning a combination maskand screen relative to a light sensitized surface comprising a framemember having a central opening, a plate-like member rotatably supportedon said frame member and having a central opening superposed withrespect to the opening in the frame member, a pair of superposed membershaving central openings therethrough communicating with each other andwith the openings in the said plate-like member and frame member, meansmovably supporting one of the said pair of members on the other of saidpair and the said other of said pair of members on said plate-likemember for individual rectilinear movement of said pair of members atright angles relative to each other and parallel to said plate-likemember, separate means for effecting rectilinear movement of each ofsaid pair of members a predetermined distance upon each actuationthereof, and means on the said one of said pair of members forsupporting a combined mask and screen thereon over the opening therein,whereby the said mask and screen may be sequentially rectilinearly movedrelative to the frame member so as to occupy any of four predeterminedpositions disposed in rectangular arrangement, and the said mask andscreen may also be rotated to a desired angular position relative to theframe.

2. An apparatus as defined in claim 1 and wherein the means foreffecting rectilinear movement of said pair of members comprise separatemeans acting on each of said pair of members respectively and normallyurging the latter each to a predetermined "position thereof, andseparate manually operable means for each member of said pair and actingthereon when operated to move the associated member of said pair toanother predetermined position thereof.

3. An apparatus of the type described for positioning a combination maskand screen relative to a light sensitized surface comprising a'iramemember having a central opening, a disk rotatably supported on saidframe member and having a central opening superposed with respect to theopening in the frame member, means for releasably locking said disk tosaid frame member to secure the disk at a selected position, a pair ofsuperposed members having central openings therethrough communicatingwith each other and with the openings in the said disk and frame member,means supporting one of the said pair of members on the other of saidpair and the said other member of said pair on said disk for individualrectilinear movement of said pair of members each between twopredetermined positions at right angles relative to each other andparallel to said disk, separate means for effecting movement of each ofsaid pair of members a predetermined distance upon each actuationthereof, and means on the said one of said pair of members forsupporting a combined mask and screen thereon over the opening therein,whereby the said mask and screen may be sequentially rectilinearly movedrelative to the frame member so as to occupy any of four predeterminedpositions disposed in rectangular arrangement, and the said mask andscreen may also be rotated to and locked in a desired angular positionrelative to the frame.

4. An apparatus as defined in claim 3 and further comprising cooperatingindicia upon said disk and frame member indicating differentpredetermined angular positions of said disk relative to the framemember.

5. An apparatus of the type described for pcsitioning a combination maskand screen relative to a light sensitized surface comprising a framemember having a central opening, a disk rotatably supported on saidframe member and having a central opening superposed with re spect tothe opening in the frame member, a pair of superposed members havingcentral openings therethrough communicating with each other and with theopenings in the said disk and the frame member, means supporting one ofthe said pair of members on said disk and. guiding the said one memberfor rectilinear movement in a plane parallel to said disk, means on saidone member supporting the other of 13 said pair of members thereon andguiding it for rectilinear movements at right angles relative to thesaid on member and parallel to said disk, means on the said diskengaging the said one of said pair of members to effect rectilinearmovement thereof from one to the other of two predetermined positions afixed distance apart, means on the said one of the pair of membersengaging the other member of said pair for effectin rectilinear movementof the said other member relative to said one member from one to theother of two predetermined positions a fixed distance apart, and meanson the said other of said pair of members for supporting a combined maskand screen thereon over the opening therein, whereby the said mask andscreen may be sequentially rectilinearly moved relative to the framemember so as to occupy any of four predetermined positions disposed inrectangular arrangement, and the said mask and screen may also berotated to a desired angular position relative to the frame.

6. An apparatus of the type described for pcsitioning a combination maskand screen relative to a light sensitized surface comprising a framemember having a central opening, a disk rotatably supported on saidframe member and having a central opening superposed with respect to theopening in the frame member, a pair of superposed members having centralopenings therethrough communicating with each other and with theopenings in the disk and the frame member, means supporting one of thesaid pair of members on said disk and guiding the said one member forrectilinear movement in a plane parallel to said disk, means on said onmember maintaining the other of said pair of members thereon and guidingthe said other member for rectilinear movements at right angles relativeto said one member and parallel to said disk, means on the said diskengaging the said one of said pair of members to effect rectilinearmovement thereof from one to the other of two predetermined positions afixed distance apart, means to retain the said one member in theposition to which it has been moved, means on the said one of the pairof members engaging the other member of said pair for effectingrectilinear movement of the said other member relative to said onemember from one to the other of two predetermined positions a fixeddistance apart, means to retain the said other member in the position towhich it has been moved, and means on the said other of said pair ofmembers for supporting a combined mask and screen over the openingtherein, whereby the said mask and screen may be sequentially movedrectilinearly relative to the frame member so as to occupy any of fourpredetermined positions disposed in rectangular arrangement, and thesaid mask and screen may also be rotated to a desired angular positionrelative to the frame.

7. An apparatus as defined in claim 6 wherein the means for moving eachof said pair of members each include a cam surface cooperating with theassociated member of said pair of members to effect movement thereof inone direction, resilient means normally urging each of said pair ofmembers in the opposite direction, and the means to retain the membersof the said pair of members in a given position comprise separate meanscooperating with each cam surface to hold it in either of two positionsthereof.

8. An apparatus as defined in claim 7 wherein each cam surface isprovided by a rockable member having a portion eccentric with respect toits axis of rocking with a separate arm portion connected to each ofsaid rockable members to effect rocking thereof, and the said means toretain a member of said pair of members in a given position cooperateswith the associated one of said arm portions.

9. An apparatus as defined in claim 8 and wherein the means cooperatingwith each of said arm portions to retain it and the associated member ofsaid pair of members in either of two predetermined positions comprisesa member normally stationary with respect to the associated arm portionsand supported for replacement by a similarly shaped member which isadapted to hold the associated arm portion in two predeterminedpositions a different distance apart thereby adapting the apparatus foruse with a different combined mask and screen.

1 0. An apparatus of the type described for positioning a combinationmask and screen relative to a light sensitized surface comprising aframe member having a central opening, a platelike member rotatablysupported on said frame member and having a central openin superposedwith respect to the opening in the frame member, a pair of superposedmembers having central openings therethrough communicating with eachother and with the openings in the said plate-like member and framemember, means supporting one of the said pair of members on the other ofsaid pair and the said other of said pair of members on said plate-likmember, means for effecting individual rectilinear movement of said pairof members each between two predetermined positions with the movementsbeing at right angles relative to each other and parallel to saidplate-like member, means on the said on of said pair of members forsupporting a combined mask and screen thereon over the opening therein,means for removably supporting a body having a light sensitized surfaceparallel with said frame member, and means for varying the distancebetween said frame member and the means supporting th said body whilemaintaining the parallel relationship therebetween, whereby the saidcombined mask and screen may be sequentially rectilinearly movedrelative to the body with the light sensitized surface so as to occupyany of four predetermined positions disposed in rectangular arrangementand the said mask and screen may also be rotated to a desired angularposition relative to said body while supported at a desired distancetherefrom.

11. An apparatus as defined in claim 10 and further comprising meanscooperating with the said distance varying means to indicate theseparation between the said frame member and the means for holding abody with a sensitized surface.

12. An apparatus as defined in claim 10 wherein the said means forvarying the distance between the body with a light sensitized surfaceand the combined mask and screen supported on one of said pair ofmembers includes a plurality of spaced motion transmitting membersextending in parallel relationship and providing an operative connectionbetween said frame member and the means for supporting the body with thesensitized surface, and means to simultaneously move each of said motiontransmitting members.

13. An apparatus of the type described for positioning a combinationmask and screen relative to a light sensitized surface comprising afirst plate-like member having an opening therethrough, means on saidmember for removably supporting a combined mask and screen over saidopening, a second plate-like member having a central opening, meanssupporting the first member on the second member and guiding the firstmember for limited rectilinear movement transversely of said secondmember and parallel therewith with the openings in said membersmaintained in communication, a disk having a central opening, means onthe said disk supporting the second member thereon and guiding thelatter for limited rectilinear movement parallel with said disk and atright angles relative to the movement of said first member with theopening of said disk maintained in commu nication with the openings ofsaid first and second members, means including a manually rockableeccentric mounted on said second member and cooperating with the firstmember to effect the rectilinear movement of the latter when the saideccentric is rocked, means including a manually rockable eccentricmounted on said disk and cooperating with the second member foreffecting the rectilinear movement of the latter when the last-mentionedeccentric is rocked, a frame member having a central opening, and

means rotatably supporting said disk on said frame member with theiropenings in commuv.nication with each other and with the openings in thesaid first and second members, whereby the said mask and screen may besequentially rectilinearly moved relative to the frame memher so as tooccupy predetermined positions disposed in rectangular arrangement andmay also be rotated to a desired angular position relative to the framemember.

14. An apparatus as defined in claim 13 and wherein the means for movingthe said first and second members each further include means cooperatingwith the eccentric thereof to locate and retain the latter in either oftwo predetermined positions each corresponding to one predeterminedposition of the member moved by the eccentric so that the mask andscreen may be rectilinearly moved to four predetermined positions.

15. An apparatus of the type described for positioning a combinationmask and screen relative to a light sensitized surface comprising afirst plate-like member having an opening therethrough, means on saidmember for removably supporting a combined mask and screen over saidopening, a second plate-like member having a central opening, meanssupporting the first member on the second member and guiding the firstmember for limited rectilinear movement transversely of said secondmember and parallel therewith with the openings in said membersmaintained in communication, a disk having a central opening, means onthe said disk supporting the second member thereon and guiding thelatter for limited rectilinear movement parallel therewith and at rightangles relative to the movement of said first member with the opening ofsaid disk maintained in communication with the openings of said firstand second members, means including a manually rockable eccentricmounted on said second member and cooperating with the first member toeffect the rectilinear movement of the latter when the said cccentric isrocked, means including a manually rockable eccentric mounted on saiddisk and cooperating with the second member for efiecting therectilinear movement of the latter when the last-mentioned eccentric isrocked, a frame member having a central opening, means rotatablysupporting said disk on said frame member with their openings incommunication, and means for releasably locking said disk to said framemember, whereby the said mask and screen may be sequentiallyrectilinearly moved relative to the frame member so as to occupypredetermined positions disposed in rectangular arrangement and may alsobe rotated to a desired Jangu lar position relative to the frame member.

16. An apparatus of the type described for positioning a combinationmask and screen relative to a light sensitized surface comprising afirst plate-like member having an opening therethrough, means on saidmember for removably supporting a combined mask and screen over saidopening, a second plate-like member having a central opening, meanssupporting the first member on the second member and guiding the firstmember for limited rectilinear movement transversely of said secondmember and parallel therewith with the openings in said membersmaintained in communication, a disk having a central opening, means onthe said disk supporting the second member thereon and guiding thelatter for limited rectilinear movement parallel with the disk and atright angles relative to the movement of said first member with theopening of said disk maintained in communication with the openings ofsaid first and second members, means including a manually rockableeccentric mounted on said second member and engaging the first member toeffect the rectilinear movement of the latter to either of two spacedpredetermined positions, means including a manually rockable eccentricmounted on said disk and cooperating with the second member foreffecting the rectilinear movement of the latter to either of two spacedpredetermined positions, a frame member having a central opening, meansrotatably supporting said disk on said frame member with their openingsin communication, mean for releasably locking said disk to said framemember, means for removably supporting a body having a light sensitizedsurface in a position parallel with said frame member, and means forvarying the distance between said frame member and the means supportingsaid body while maintaining the parallel relationship therebetween,whereby the said combined mask and screen may be sequentiallyrectilinearly moved relative to the body with the light sensitizedsurface so as to occupy any of four predetermined positions disposed inrectangular arrangement, and the said mask and screen may also berotated to a desired angular position while supported at a desireddistance from the said body.

WILLIAM CARL HUEBNER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,060,982 Huebner V May 6, 1913 1,471,773 Bowen 1 Oct. 23,1923 1,654,070 Corlett Dec. 27, 1927 1,911,142 Cahill May 23, 1933

